Characteristics of an ejection orifice surface of an ink jet recording head are important for providing satisfactory ejection performance. When an ink well remains in the vicinity of an ejection orifice, a flying direction of an ink droplet is deflected and an ejection rate of the ink droplet lowers in some cases. Therefore, as a method of ejecting ink with good precision, there is given a method involving subjecting the vicinity of an ejection orifice portion to water-repellent treatment. In general, a silicon-containing compound, a fluorine compound, or the like is used as a material for forming a water-repellent surface. The fluorine compound is suitable for ejecting inks containing various solvents and colorants like the ink jet recording head. As the fluorine compound exhibiting satisfactory water repellency, for example, there are known a perfluoroalkyl-group-containing compound and a perfluoropolyether-group-containing compound. Of those, a perfluoropolyether-group-containing compound has attracted attention from the viewpoint of environmental suitability in recent years.
Further, in order to maintain a condition of an ejection orifice portion surface of the ink jet recording head, ink remaining on the surface is regularly wiped with a rubber blade or the like in some cases. Therefore, the ejection orifice portion surface after the water-repellent treatment is required to have high durability against abrasion. Patent Literature 1 discloses an example using a compound having a perfluoropolyether group and an alkoxysilyl group as a water-repellent treatment method by which a water-repellent film having high durability is provided.